Glass articles are usually made by forming molten glass into the desired shapes. It is also known to make glass articles by casting a mixture of glass powder, with or without a binder, into a mold and then heating the mold to sinter the glass powder. An example of a conventional glass powder casting method is described in U.S. Pat. No. 4,849,001 to Drake et al. which claims sintering water-soluble glass powder at a temperature that is in the range of ˜10 to +25° C. of its glass softening temperature, Ts. However, both of the aforementioned methods have process limitations that restrict the geometric shapes of the articles that may be manufactured monolithically, i.e., without fusing or gluing together two or more component parts.
It is also known to make glass articles from glass powder by three-dimensional printing techniques. For example, U.S. Patent Application Publication No. US 2006/0208388 A1 of Bredt et al. describes the making of glass articles consisting of glass powder bonded together by polymer. U.S. Pat. No. 7,422,713 B2 to Oriakhi et al. describes a similar way to make glass articles consisting of glass beads bonded together by a hydrated cement. Recent reports on the Internet from the University of Washington describe the use of what they call their “Vitraglyphic process” to create glass objects using a conventional 3-D printer and then heating to sinter the glass powder to result in fired glass objects that are light and quite porous, such that they are essentially glass sponges. See http://www.physorg.com/news173022660.html (visited Oct. 21, 2009) and http://open3dp.me.washington.edu/?p=20 (visited Oct. 21, 2009). The problem with these methods, however, is that they do not result in useful glass articles having near full density.